Tunable vibration dampers and methods of manufacture and tuning
View Patent ↗Embodiments are directed to tunable damper embodiments and methods of using the same for damping resonant and non-resonant vibrations present within an object that the tunable damper is secured to. In some cases, the tunable damper may be tuned before, during or after being secured to an object.
1. A tunable vibration damper assembly, comprising:
a housing including at least one sidewall, at least one base plate and at least one cover plate, the housing further comprising at least one chamber configured to receive a damper mass;
the damper mass disposed in the at least one chamber, the damper mass having a rectangular box shape including a top surface and a bottom surface;
a first mass engaging member positioned adjacent the top surface of the damper mass and a second mass engaging member positioned adjacent the bottom surface of the damper mass, wherein the first mass engaging member and the second mass engaging member are comprised of a flat plate having a first surface parallel to a second surface with the second surface facing the damper mass, the flat plate including a resilient spring material configured to elastically support the damper mass;
a first pair of engaging devices positioned between the first mass engaging member and the top surface of the damper mass and a second pair of engaging devices positioned between the second mass engaging member and the bottom surface of the damper mass, the first pair of engaging devices comprising a pair of extruded elongate bodies extending along the length of the top surface of the damper mass and engaging the second surface of the first mass engaging member, the second pair of engaging devices comprising a pair of extruded elongate bodies extending along the length of the bottom surface of the damper mass and engaging the second surface of the second mass engaging member;
at least one load mechanism threadedly engaged to a load plate, the load plate comprising a flat plate having a first side parallel to and facing the top plate and a second side including engaging member supports extending along opposing sides of the second side of the load plate with each of the engaging member supports having a sloped surface, wherein the load mechanism, load plate and engaging member supports are configured to apply a biasing force to the first and second mass engaging members; and
damped elements secured to the first surface of the first mass engaging member, the damped elements positioned along opposing sides of the first surface of the first mass engaging member, and the damped elements positioned between the first mass engaging member and the sloped surfaces of the engaging member supports, the damped elements configured to undergo shear deformation upon movement of the damper mass.
2. The tunable vibration damper assembly of claim 1 , wherein the damped elements are comprised of one or more layers of viscoelastic polymers.
3. The tunable vibration damper assembly of claim 1 , wherein movement of the damper mass causes the damped elements to undergo shear deformation.
4. The tunable vibration damper assembly of claim 1 , the first and second mass engaging members are comprised of one or more spring quality metals.
5. The tunable vibration damper assembly of claim 1 , wherein a thickness of the flat plates of first and second mass engaging members are is between 0.01 and 0.1 inches.
6. The tunable vibration damper assembly of claim 1 further comprising an optical table wherein the housing of the tunable vibration assembly is operatively coupled to the optical table.
7. The tunable vibration damper assembly of claim 1 further including an access port in communication with the load mechanism.
8. The tunable vibration damper assembly of claim 1 , wherein adjustment of the load mechanism affects the effective flexibility of the first and second mass engaging members.
9. The tunable vibration damper assembly of claim 1 , wherein the effective flexibility of the first and second mass engaging members are adjustable at least one of before, during and after the tunable vibration damper assembly is operatively coupled to an object.
10. The tunable vibration damper assembly of claim 1 including a locking feature operatively coupled to the load mechanism which prevents occasional disturbance of the load mechanism.
11. The tunable vibration damper assembly of claim 1 , wherein the engaging member supports includes the sloped surfaces which allow for a change in a contact area between the sloped surfaces and the damped elements as a result of a change in the biasing force.
12. The tunable vibration damper assembly of claim 11 , wherein an increase in the contact area between the sloped surfaces and the damped elements reduces the effective flexibility of the first mass engaging member.